diplomatic facility in benghazi, libya. ambassador chris stevens and three other americans were killed in that attack. democrats say this new investigation is a ploy to embarrass the white house before november elections, but republicans say the administration just hasn't told the truth. nancy cordes reports. >> reporter: for nearly 20 months, four separate committees in the republican-led house have held dozens of hearings, examined documents, and released reports on the benghazi attacks, but house speaker john boehner said today a special new committee is needed because the obama administration is "intent on obstructing the truth about benghazi," and "willing to defy subpoenas." boehner had long argued a special committee was unnecessary, but aides say he unnecessary, but aides say he changed his mind this week after the white house released previously unseen e-mails in response to a lawsuit. one of the e-mails was sent three days after the libyan attack. deputy national security adviser ben rhodes wrote in public appeara